Why is Leave in Elspeth's Expert and Master decks?

Leave is a card that bounces all creatures you control to your hand. I could see doing that if there's some effect on replaying the creature, like Angel of Sanctions (also in the Master Deck), which destroys a target creature upon entering the battle field. Though that'd be a total of 29 mana to accomplish a second destroy--a hefty price. (13 mana for Leave, and 16 to recast Angel of Sanctions)

There are no other creatures in either deck that have on summon effects. How is this supposed to synergize with the other cards in these decks?

Under what circumstances would it be worth the 13 mana to bring your creatures back to your hand? I saw someone say that it doesn't work with Act of Treason (the stolen card goes to the owners hand), so what would you use this for?

The only thing I could think of would be to use it, then cast Fumigate (which is in neither of the decks), then recast your creatures, but that would also be a very mana intensive move. Maybe if you were trying to hit a Commander objective? Or a Slow and Steady one? Is the point to get to the aftermath ability (Chance)?

I can certainly see the utility of Chance if you had a bad hand. Are you supposed to cast this when you don't have any creatures to bounce to get the chance to, well, cast Chance?

Even then, I could see Chance backfiring if you liked your hand and you accidentally triggered it in a cascade.

oh, man, I just looked at the MTG version of the card (here). You can choose which permanents to return to your hand and Chance lets you discard however many cards you want and then draw that many. And the Leave part only has a converted mana cost of 2. That's way more useful than the MTGPQ counterpart.

Am I missing some utility of this card? Or is it just a bad rare?